An on-demand printing system for an information terminal such as a PC, a smart phone, a tablet and the like, includes an image forming apparatus and a server that are connected with each other through a network. The system temporarily collects printing data sent from the information terminal in the server, and a user instructs, from a given image forming apparatus, to retrieve the printing data stored in the server to execute printing.
An electrophotographic type image forming apparatus that heats a toner image transferred to an image receiving medium such as a printing sheet and the like by a fixing device to fix the toner image on the image receiving medium, may be used as an image forming apparatus. If no operation is carried out during a given time, the image forming apparatus transitions into a sleep mode from a standby mode, which corresponds to a print-ready state. The image forming apparatus transitions into the sleep mode to cut off the power supplied to the part that is not needed to save power. The image forming apparatus in the sleep mode needs to be resumed from the sleep mode to the standby mode to execute a next print job.
When such an image forming apparatus is connected to a network, a user has to move to the image forming apparatus and look at a display screen of the image forming apparatus to confirm whether the image forming apparatus is in the standby mode or the sleep mode. If the image forming apparatus is in the sleep mode, the user needs to press an operation button to cancel the sleep mode and transition the image forming apparatus into the standby mode.
That is, when the user moves to the image forming apparatus to execute printing and selects printing data to be retrieved from the server for printing from options displayed in the display screen, the image forming apparatus is resumed from the sleep mode to the standby mode.
The image forming apparatus that receives the operation of the user is resumed from the sleep mode to the standby mode. However, the image forming apparatus will require a certain amount of time before transitioning from the sleep mode to the standby mode; thus, the user has to wait for the start of printing in front of the image forming apparatus.